#include <iostream>
#include<unistd.h>
#include<sys/types.h>

using namespace std;

int main()
{   
    pid_t id = fork();
    if(id == 0)
    {
       
        cout << "child" << endl;
    }
    else if(id > 0)
    {
        cout << "father" << endl;
    }
    else
    {
        cout << "error" << endl;
    }

    return 0;
}

